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Vesta's surface is characterized by abundant impact craters, some with preserved ejecta blankets, large troughs extending around the equatorial region, enigmatic dark material, and widespread mass wasting, but as yet an absence of volcanic features. Abundant steep slopes indicate that impact-generated surface regolith is underlain by bedrock. Dawn(More)
ESA's Mars Express has successfully completed its nominal mission of one Martian year covering about 25% of the surface in stereo and color with resolutions up to 10 m/pixel by its high-resolution stereo camera (HRSC). Mars Express is now in its extended mission phase, during which much of the remaining part of the Martian surface is envisaged to be covered(More)
Titan is the only satellite in our Solar System with a dense atmosphere. The surface pressure is 1.5 bar (ref. 1) and, similar to the Earth, N2 is the main component of the atmosphere. Methane is the second most important component, but it is photodissociated on a timescale of 10(7) years (ref. 3). This short timescale has led to the suggestion that Titan(More)
–The Dawn spacecraft mission has provided extensive new and detailed data on Vesta that confirm and strengthen the Vesta–howardite–eucrite–diogenite (HED) meteorite link and the concept that Vesta is differentiated, as derived from earlier telescopic observations. Here, we present results derived by newly calibrated spectra of Vesta. The comparison between(More)
Although water vapour is the main species observed in the coma of comet 67P/Churyumov-Gerasimenko and water is the major constituent of cometary nuclei, limited evidence for exposed water-ice regions on the surface of the nucleus has been found so far. The absence of large regions of exposed water ice seems a common finding on the surfaces of many of the(More)
Introduction: Compositionally, the surface of Enceladus is build up almost completely by water ice [1]. However, distinct variations in the size of water ice particles are apparent. As the band depths of water ice absorptions are sensitive to particle size, given constant abundance and viewing geometry, absorption depths can be used to map these variations(More)
Introduction: Aeolian processes affect much of the uppermost surface of Mars. Wind will transport pre-eroded material and pile it up into various bedforms. Sub-aerial transport of granular material via saltation and traction typically requires sand-sized particles on Earth and also on Mars [1]. Edgett and Parker (1998) [2] characterized aeolian bedforms(More)
Carbon dioxide (CO2) is one of the most abundant species in cometary nuclei, but because of its high volatility, CO2 ice is generally only found beneath the surface. We report the infrared spectroscopic identification of a CO2 ice-rich surface area located in the Anhur region of comet 67P/Churyumov-Gerasimenko. Spectral modeling shows that about 0.1% of the(More)
The VIRTIS (Visible, Infrared and Thermal Imaging Spectrometer) instrument on board the Rosetta spacecraft has provided evidence of carbon-bearing compounds on the nucleus of the comet 67P/Churyumov-Gerasimenko. The very low reflectance of the nucleus (normal albedo of 0.060 ± 0.003 at 0.55 micrometers), the spectral slopes in visible and infrared ranges (5(More)
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